1. Field of the Invention
This invention relates to novel arthroscopic surgical instruments and novel methods for their use. More particularly, it relates to miniature tools having utility in connection with methods for performing a cervical discectomy.
2. Description of the Prior Art
Neck pain is sometimes caused by the pressure of a ligament bearing against the spinal cord. The pressure can be surgically relieved by debulking, i.e., removing some of the nucleus beneath the ligament so that the ligament can return to its normal position.
In highly invasive, i.e., non-arthroscopic surgery, nucleus debulking is performed by making a relatively large incision and cutting through the membrane that overlies the ligament and through the ligament in order to reach the nucleus. The nucleus is cut and sufficient amounts thereof are removed to thereby remove pain-causing pressure.
In arthroscopic surgery, a small incision is made and the incision is dilated so that surgical tools may be introduced therethrough. More particularly, after the initial incision is made, a dilator tube is introduced thereinto to increase the diameter of the incision. The dilator tube in common use has a rather large inside diameter so that it can accept the various arthroscopic tools that are introduced thereinto as the operation proceeds.
In arthroscopic surgery, one of the tools usually employed to debulk the nucleus is known as a punch tool because it operates something like a paper punch, i.e., a shearing action accomplishes the desired cutting. More particularly, a typical punch tool has an elongate neck and the shearing mechanism is positioned at the distal end of that neck. A pair of handle members at the proximal end of the neck are squeezed by the surgeon and the squeezing action causes a first part of the shearing mechanism to slide with respect to a stationary second part of that mechanism, and nucleus matter between said parts is sheared from the main body of nucleus matter.
The cervical discectomy punches of the type just described operate in a batch mode, i.e., they shear a single piece of tissue for each entry through the incision to the surgical site. After each shearing action, the punch is withdrawn, an irrigation tool is inserted to irrigate the site and place the sheared piece of nucleus into suspension, the irrigation tool is withdrawn, a suction tool is inserted to vacuum the irrigation fluid and the sheared piece, the suction tool is withdrawn, and the punch tool is inserted for another shearing action. Thus, a surgeon might be required to make dozens of entries and exits through an incision in the course of a surgical procedure when using a conventional, one bite punch instrument. Such multiple entries, exits, and re-entries obviously extend the time required to perform the surgical procedure, and tire the surgeon and surgical assistants.
Since arthroscopic surgical techniques require much smaller incisions than highly-invasive surgery, they permit much faster patient recovery and reduce the length of hospital stays and save the expenses associated therewith. However, there is a need for an improved method of dilating the initial incision so that tissue trauma arising from dilation is minimized. Moreover, improved instruments and surgical procedures are needed.
There is also a need for an improved multiple function tool for performing multiple functions such as laser irradiation, irrigation, suction, and the like so that multiple re-entries to the surgical site can be minimized.
The prior art, however, when considered as a whole at the time the present invention was made, neither taught nor suggested to those of ordinary skill in this field how the dilation process could be improved, how the known arthroscopic tools could be improved, or how the debulking procedure itself could be improved.